The scariest ever was when the Ravana showed up in The Great Hunt. It was the first time I came up close to a ship of destroyer size.
It was like, everything was normal, our two corvettes just decimated everything that jumped in, until some ****ing
monstrous hell of a ship jumped in...

The scary part is that I came quite close to it. Being very misty, it was as if you were swimming underwater, when suddenly a Blue Whale appears, right in front of you.

I seriously thought there was some kind of a Boss Battle next, and that this warship...or so it seemed more like a monster...was behind all this racket. It looked just...invincible. I remember doing sort of a suicide run, just to increase the dramatic effect, towards it from under, firing all my lasers, missiles, EVERYTHING...I wanted to KILL THIS THING! It was, however, impossible to stop, given my weapons. So I just...jumped out.
The briefing that followed it didn't seem very dramatic, I expected more of a "we have encountered a gigantic warship earlier, whose intimidating appearance has caused utter terror and shock to our fellow pilots. We are now scrambling all available warships in the vicinity and the surrounding systems and are preparing a mass attack. The capabilities of this warship exceed any of which we have known. The destruction of this target, if and only if indeed we succeed, will deal a devastating blow to the Shivan advance" kind of speech.
However, it was more like a "we've encountered a new type of destroyer. Now get back to work and we'll send wingmen with you. Just destroy that warship." speech, which sort of sounded anti-climactic.
The "Dive Dive Dive" thing pretty sure surprised me, but was no reason to be scared of...on the first attempt, I even escaped it, unlike some of you

.
The Sathanas' appearance didn't scare me, as it was predictable that a "Juggernaut" would appear as I've read in the Internet. In other words, I already expected a huge Shivan ship to appear in the game.
Another memorable one was in the Procyon Insurgency. I just
had to destroy that hell of a super-powered Hades. At that time my skill level wasn't good, and I hadn't much experience with battling massive capital ships yet, so I ended up cheating by just simply spamming Helii on it.
After a tough, hot battle, I thought it was over. The destroyers nearby were powering their main guns, and fired their epic beam cannons which shred apart the seemingly invincible ship...
...until....

...
...there was this cinematic, of Dasmar's ship blasting in a majestic fireball...but wait...
...the Knossos is spinning rapidly...faster...faster...faster....hell faster still...there's
something going on...something
terrible has to come out of that mad portal....

...WHOOSH! A ****ing
colossal Inferno Ancient-esque warship appears! What is this monstrosity!

...and I have to destroy it! Destroy THAT!
